[This message has been edited by La fiera (edited 03-29-2021).]

[This message has been edited by La fiera (edited 03-29-2021).]

quote Originally posted by Will: Well that one was on you for welding the spherical bearing shells in without tacking in place

I wonder if I still could have made up enough space, it was really tight. but you're not wrong, I should have waited to do it until I had everything ready.

quote Originally posted by Will: Yeah, adjustable UCAs and a slightly longer steering shaft (with EPAS & Steering quickener ) would add polish to the anti-dive changes.

like this?

https://grassrootsmotorspor...i-308/148959/page67/


Also, I had a thought, on the Pig Rig, I heated the collapsing part of the column with a heat gun, and was able to extend it a small amount. potentially, I could do the same with a Fiero shaft. not sure how much extension is safely available though.

quote Originally posted by zkhennings: If you are getting a firm pedal when the car is off then I would be surprised if you have any serious problems, the master is probably too small. I have a full sized Blazer MC in my Fiero to accommodate for the Grand Am brakes at all four corners, the Fiero reservoir replaces the stock Blazer one perfectly.

I found a potential air leak in the combination valve.... I had an OK pedal with the stock master prior to the front suspension work, not great by any means, but also not blatantly unsafe like it is now. I figured it just needed to be bled better.

Did the reservoir just pull off, or is there some kind of latch or something holding it on? I've been looking at some larger truck MC's the only other cylinder I had known to work for sure was a S-10 blazer.


according to O'reilly's and summit racing, a mid 90's C3500HD has a ~1.57" MC. which would probably work well if it's actually that size, and has fittings that work.

quote Originally posted by pmbrunelle: Besides actually adding some trail, there's also the EPAS idea: 1. Estimate the forces acting on the front contact patches 2. Using a simulated model of the actual butchered-together front suspension, compute the steering column torque that would be felt by the driver (without any intervention) 3. Using a simulated model of a correctly-designed front suspension, compute the steering column torque that SHOULD be felt by the driver's arms 4. Use the EPAS to make up the torque difference between the actual and ideal suspension 5. Enjoy your artificial ride?

yeah, I've been wondering about it, and how tuning a setup like that would work, making it fit can't be too hard, but making it work...

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"I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."

cognita semper

quote Originally posted by ericjon262: yeah, I've been wondering about it, and how tuning a setup like that would work, making it fit can't be too hard, but making it work...

Well firstly, it would be pretty dicey in the sense that the car has one personality when everything is working right, and then the actual steering feel when the electronics are inoperative. So the driver could be unprepared for the car's true steering feel... refer to Boeing 737 MAX.

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I hesitate to consider "self-centering" as a goal to achieve in a steering system.

In my view, it is important that the torque transmitted to the driver be proportional to the lateral contact patch force. This is the information that can help a driver to drive safely and quickly. Other sources of torque (such as jacking the front of the car as you turn) obscure the important information the driver needs.

Naturally, if you transmit the tires' lateral force to the steering wheel, the steering wheel will self-center, but that is a side-effect of the true goal.

Some folks have wanted a simple self-centering torque; torque overlay proportional to the steering angle. The electric equivalent of a mechanical spring. However, I think that this is a good way to make a driver crash. If a driver is taking a corner too fast, he needs to feel the steering get light as the front tires wash out. If the steering torque still feels high, then the driver might be duped into thinking that there's still grip available.

A driver can eventually adapt to a car that lies through its steering, but why?

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At some point I did study synthetic steering feel for vehicles which don't have any (such as stuff with hydraulic steering), but it didn't get beyond the reading stage. With accelerometers and such you can figure what's going on with the tires. Also, depending on how inaccurate you want the estimated tire force to be, you can reduce the number of sensors.

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I did once try a "steer-by-wire" setup.

I used a master EPS connected to a steering wheel.
I used a slave EPS connected to the rack of a vehicle.
There was no mechanical link between the only, only a CAN bus.

The master sent its steering wheel angle to the slave.
The slave adjusted the current in the electric motor in order to make the actual position follow the position ordered by the master.
Electric motor current is a proxy for torque; the slave reported back to the master how much current it was injecting into the motor.
The master injected the amount of current reported by the slave into its own electric motor, applying a torque to the steering wheel.

Surprisingly, it felt pretty real, without much tinkering required.

Of course, none of the parts I used for this setup were designed/rated for steer-by-wire, so it would have been too dicey to try this on a running/driving vehicle. I just tried it on a parked vehicle.

quote Originally posted by Will: I think the whole idea behind good suspension design is to make kludgey fake tuning shenanigans unnecessary

I think a semi-synthetic feel setup would be a good fit good for someone doing a stock-style sleeper build. Somewhere, there must exist a manager that would like to solve an expensive hardware problem with a software patch... The ultimate stock-style project car build will reflect a normal amount of cost-cutting and dysfunction.

For example, there are people who restore cars, but they don't aim for the smoothest/shiniest paint. They instead seek to duplicate the factory paint runs.

[This message has been edited by pmbrunelle (edited 03-30-2021).]